Gallium nitride (GaN) is a refractory semiconducting material with a wide optical bandgap and can be doped n-type and p-type. More particularly, light emitting devices, such as light-emitting diodes (LED) and diode lasers, have met with an overwhelming commercial success, with LEDs now increasingly replacing inefficient incandescent lamps and even fluorescent lighting fixtures. In addition, GaN has a low electron affinity (≅2.7 eV) as well as a high chemical and mechanical stability and has therefore attracted attention as a material for field emission devices. Field emission cathodes fabricated from GaN should have longer lifetimes because of their high sputtering resistance and low sensitivity to residual gases, especially oxygen.
The emission current from a field emission cathode depends on the electric field at the tip of the field emitter. Decreasing the size of the tip by using nanotips as an electron source can significantly reduce power consumption of a display device. The use of nanotip electron sources also reduces the form factor of the display.
For these and other reasons that will become apparent, it would be desirable to provide a process that produces GaN nanostructures, such as nanotubes and nanowires, with controlled chemical and physical properties.
It would also be desirable to produce nanoscale devices for electronic and sensing applications that incorporate such GaN nanostructures.